optimize decrypt

lib/pdf_utils.rb

@@ -15,17 +15,11 @@ module PdfUtils
   end
 
   def decrypt(data, password)
-    encrypted_doc = HexaPDF::Document.new(io: StringIO.new(data), decryption_opts: { password: })
-
-    decrypted_doc = HexaPDF::Document.new
-
-    encrypted_doc.pages.each do |page|
-      decrypted_doc.pages << decrypted_doc.import(page)
-    end
-
     decrypted_io = StringIO.new
 
-    decrypted_doc.write(decrypted_io, validate: false)
+    Pdfium::Document.open_bytes(data, password) do |doc|
+      doc.save(decrypted_io, flags: Pdfium::FPDF_REMOVE_SECURITY)
+    end
 
     decrypted_io.tap(&:rewind).read
   end

lib/pdfium.rb

@@ -444,6 +444,7 @@ class Pdfium
   }.freeze
 
   class PdfiumError < StandardError; end
+  class PasswordError < PdfiumError; end
 
   def self.error_message(code)
     PDFIUM_ERRORS[code] || "Unknown error code: #{code}"
@@ -512,7 +513,9 @@ class Pdfium
 
     return if error_code == FPDF_ERR_SUCCESS
 
-    raise PdfiumError, "#{context_message}: #{error_message(error_code)} (Code: #{error_code})"
+    error_class = error_code == FPDF_ERR_PASSWORD ? PasswordError : PdfiumError
+
+    raise error_class, "#{context_message}: #{error_message(error_code)} (Code: #{error_code})"
   end
 
   # rubocop:disable Metrics